The present invention relates generally to optical network systems, and more particularly, a system and method for providing dynamic burstification of multicast traffic based on fully/partially shared multicast entities.
Data traffic over networks, particularly the internet, has increased dramatically over the past several years, and this trend will continue with increasing number of users and the introduction of new services which require more bandwidth. The enlarged volume of internet traffic requires a network with high capacity routers capable of routing unicast and multicast data packets with variable lengths. A unicast data packet is a data packet generated from an application requiring point-to-point communication. The unicast data packet is switched through a series of electronic packet switching systems to its destination. A multicast data packet is a data packet generated from an application requiring point-to-multipoint or multipoint-to-multipoint communications. The multicast data packet is switched through a tree of electronic packet switching systems to multiple destinations.
Different approaches advocating the use of optical technology in place of electronics in switching systems have been proposed, however current optical networks use only a small fraction of the bandwidth available on a single optical fiber. The emergence of dense-wavelength division multiplexing (DWDM) technology has helped to overcome the bandwidth problems encountered by current optical networks. A single DWDM optical fiber now has the capability of carrying as much as ten (10) terabits of data per second. However, this creates a serious mismatch with current switching technologies which are capable of switching data at rates of only up to a few hundreds gigabits per second.
While emerging ATM switches and IP routers can be used to switch data using the individual channels within a DWDM fiber, typically at 2.4 gigabits per second or 10 gigabits per second, this approach implies that tens or hundreds of switch interfaces must be used to terminate a single link with a large number of channels.
One approach, called optical burst-switched networking, attempts to achieve the best combination of optical and electronic switching technologies. To circumvent potential bottlenecks in electronic processing, the data unit to be transferred in the optical burst-switched network is a data burst. A data burst, or simply a burst, is a collection of one or more data packets which have a set of common attributes. An obvious example would be a common egress point in an optical burst-switched network. The electronics provide dynamic control of system resources by assigning individual user data bursts to channels on a DWDM fiber. Optical technology is used to switch the user data bursts entirely within an optical domain. Optical burst switched networks are able to switch both unicast and multicast data bursts. However, limitations of optical component technology has largely limited optical switching to facility management applications.
Previously developed optical burst-switched networking systems have performed poorly and generally tend to demonstrate the inefficiency of current optical components. For example, one prior art optical burst-switched network utilized ATM switches in the control network which made the design of the control network much more complicated and suboptimal. Other prior art optical burst-switched networks used electronic buffers in the optical routers, thus the optical burst-switched network was not purely optical. The electronic buffers did not provide end-to-end transparent optical paths for data bursts. Thus, little has been done to stimulate any serious move toward optical burst-switching.
The present invention provides a dynamic burstification system and method based on fully/partially shared multicast trees that substantially eliminates or reduces disadvantages and problems associated with previously developed systems and methods used for switching multicast data packets.
More specifically, the present invention provides a system and method for collecting multiple multicast data packets into a multicast burst according to some multicast burstification classification criteria, then switching the multicast burst through an optical burst switched network. To switch multicast data packets through an optical burst switched network according to the present invention, multicast data packets are first assembled into a multicast burst at an electronic ingress edge router according to a plurality of multicast burstification criteria (classes). The multicast burst is then switched through the optical burst-switched network to the destined electronic egress edge routers where the burst is disassembled back into multicast data packets and transmitted to its final (multiple) destinations.
The present invention provides a technical advantage by providing an optimized way to assemble multiple multicast data packets into a single multicast burst according to multiple multicast burstification classes and transmitting the multicast burst through an optical burst switched network.
The present invention provides a technical advantage by increasing the burst length of multicast traffic, thus providing increased efficiency in the transfer of multicast traffic in optical burst-switched networks.
The present invention provides another technical advantage by reducing the burst assembly time interval resulting in reduced multicast data packet latency at an electronic ingress edge router.
The present invention provides another technical advantage by reducing the amount of control traffic and control operations necessary to forward/route multicast bursts to their destinations.
The present invention provides another technical advantage since it is largely independent of the specifics of the control units of underlying optical burst-switches (e.g. ATM based) or the specifics of the optical switch matrix (e.g. may use electronic or optical buffers).